In a recent monthly Shonen Jump, they talked about an interview with Tiete Kubo. One very Interesting question was:
Shonen Jump: Why did pick Bleach as the title?
Kubo-Sensei: the title wasn't Bleach when I decided to draw a story about Soul Reapers. This was before I drew the one-shot manga that appeared in Akamaru Jump. The weapon wasn't a sword, but a scythe. Only Rukia had a scythe and the other characters used guns. At that point, the title was Snipe[as in sniper]. Right before I started drawing, I began to think that a sword would be better and realized I couldn't use Snipe as a title anymore. I began looking for a title that grasped the the bigger picture . Soul Reapers are associated with the color black, but it would have been boring to use "black." "White,"on the other hand, can suggest black as a complementary color. So I chose "bleach" to evoke the impression of the color white.
Portal 
